


Demon Blood

by ZoneRobotnik



Category: Gravity Falls
Genre: M/M, Vampire!Dipper, bill is in an unfortunate situation, mabel is a supportive sister, robbie is a vampire too, vampires are magical
Language: English
Status: In-Progress
Published: 2016-03-19
Updated: 2016-03-24
Packaged: 2018-05-27 15:12:26
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 3,475
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/6289516
Author URL: https://archiveofourown.org/users/ZoneRobotnik/pseuds/ZoneRobotnik
Summary: <blockquote class="userstuff">
              <p>Mabel used to want to meet a real vampire. Now she just wants to punch it in the face for what happened to her brother.</p>
            </blockquote>





	1. Changed

**Author's Note:**

> Gravity Falls © Alex Hirsch

Before the incident, Mabel Pines would've given anything to meet a vampire. Anything, even her blood. But, as it happened, now the only reason she wanted to meet a vampire was to yell at it for what happened to her brother.

She was at a friend's house when it happened. They were playing with dolls and drawing out backgrounds for their stories when her friend's parents got a call for Mabel to come to the hospital right away. Her twin, Dipper Pines, was found unconscious and pale in the park by himself, with some kind of puncture wound on his neck. Now, she had read enough novels to know what that meant, and when she visited him in the hospital he had a bandage around his neck and all the curtains were drawn at his request.

His parents left the room to talk to the doctor, leaving Dipper and Mabel alone in the room. He turned to look at her, and she gasped softly at the strange expression he had. “Dipper?” She approached the bed. “Are you...okay?”

“Hungry.” He admitted, looking at his hands.

“I can call the nurse.” Mabel stood up.

He nodded. “Thanks.”

Mabel started for the door when she heard a sound behind her and looked to see Dipper stepping out of bed. “Dipper, you shouldn't be moving!”

“Mabel...” He stepped towards her.

She frowned and walked closer. “Dipper, what's wrong?”

He took her wrist and pulled her closer to him. “I won't take too much...I'm just so hungry...sorry.” He moved his mouth to Mabel's neck and parted his lips. Mabel, stunned by the moment, gasped as she realized what he was doing and held onto him as he bit down.

“Ngh! D-Dipper...be careful...” She said, her painted nails digging into his arms.

They stayed like that for a bit, and then he slowly and carefully pulled his teeth out before releasing her. Mabel promptly went to where they kept the medical supplies for the nurses and got out bandages. Dipper helped her wrap her neck and then looked at the door worriedly.

“They'll ask questions...” He looked at her guiltily.

“I have a turtleneck sweater in my bag.” Mabel went to her bag and pulled it out.

“Mabel...it's almost summer.” Dipper sighed.

“So? I can knit one without sleeves. Besides, it's pretty cold today.” Mabel pulled her sweater on and smiled. “See? Out of sight, out of mind.” She gestured to her concealed neck.

He nodded, using wipes to clean up his mouth before climbing back into bed.

"Do you know who attacked you?” Mabel asked.

“No...I thought vampires only came out at night?” Dipper sighed.

“Did he sparkle?” Mabel asked.

Dipper gave her a tired look. “No, he didn't sparkle. He wore a hooded jacket, though.”

“I guess you'll have to do that.” Mabel nodded. “And pants might be a good idea, too.”

He grimaced. “Just in time for summer...”

“Well, you wanna go find the vampire that attacked you and tell him his timing stinks?” Mabel put her hands on her hips.

“You're...really lively for having just been drained of blood.” Dipper commented.

Mabel shrugged. “I got plenty of energy! Besides, it's no more than what I would've given if I donated to the blood bank.”

The doctor came in with their parents then and checked on him. “Well, you seem to be looking a lot better! Still, I'd like you to stay in bed a bit longer, so we can make sure you'll be okay.” The doctor turned to the door, where a couple police officers had entered. “Officers?”

“We just want to ask him about his attacker.” One of them assured him, and then he walked over to Dipper's bed and sat in the bedside chair. “Son, you've been through a pretty rough ordeal. Do you think you can help us prevent this from happening to anyone else?”

“The guy was in a hooded sweater...I didn't see his face.” Dipper looked at them. “He was a teenager, I think. Wore all black, and had really quiet shoes.”

“That's not much to go off of.” The officer looked discouraged.

“I'm sorry.” Dipper looked at his hands in his lap. “That's all I know.”

“Well, we'll set up patrol around that area.” The officer stood up and headed for the door. “Thank you, and I hope you get better soon. We'll find this sicko, don't worry.”

Mr. Pines walked out with them while Mrs. Pines approached the bed. “Dipper? How are you feeling?” to her relief, the boy had only been bitten by his attacker, and nothing else – seriously, what a sicko.

“I'm feeling better.” Dipper nodded. “Though...it was really scary. I don't know if I'll be able to sleep for a while.”

**–**

 

As it turned out, Dipper wasn't able to sleep at all. He kept tossing and turning, trying to sleep, but it never came. His body didn't seem to want or need it, but he was getting a gnawing hunger. He looked around and then slipped out of his bed. The IV had been removed, but he was still kept there for observation. But, he needed food. No, not food. Blood. He needed blood.

He passed by the nurse station silently, his steps soundless – so much for it being the shoes that kept him from detecting his attacker. He made his way to the stairs and down to the ground level. Strangely, no one stopped him. It was...unnerving. He caught a nurse looking in a hand-mirror to adjust her contacts and stopped short. He should be seeing himself standing behind her...why wasn't he? He shivered and walked on.

When he got outside, he looked around in confusion. Why was the traffic so oddly slow? As if to test his theory, he walked across the active street, easily dodging car after car until he was across. It was strange, and exhilarating.

“You seem to be adapting well.”

Dipper gasped and turned to see his attacked watching him. “You!”

“Nice scrubs, kid. Your powers have started to work, it looks like.” The vampire approached him. “I didn't mean to change you, you fought back and it was...unusual. Did you know you had sharp teeth even before you changed? Cut right into my hand.”

Dipper slowly nodded, recalling the metallic taste of the vampire's blood. “So...why are you here?”

“Accident or not, I caused you.” The vampire shrugged. “The least I could do is help you out a bit by giving advice. You don't want to kill humans, right?”

Dipper nodded.

“Thought so. Listen, if you lick the wound after you're done, the wound will stop bleeding. Don't ask me why, my Sire wasn't nice enough ro stick around and give me tips.” The vampire stopped in front of him. “You look pretty hungry. Let's find you some food.” He wrapped his arm around Dipper and led him along.

“Who are you, anyway?” Dipper asked.

“Name's Robbie. I'm from a town called Gravity Falls.” The vampire looked at him. “You?”

“Dipper Pines.” Dipper nodded.

“Sorry about jumping you. I went too long without feeding, and animals are a piss-poor substitute.” Robbie shook his head. “Anyways, you may have noticed that the world is slowed down. Actually, we're just moving faster. Way faster.”

“Is there a cure?” Dipper asked.

“If there was, I wouldn't be a vampire still.” Robbie shook his head. “But, I am looking into one.”

“Okay.” Dipper nodded.

“I gotta tell ya, this whole thing stinks. I'm part of a band, but we don't show up on camera or in mirrors! Which means I gotta avoid cameras and mirrors, or put on makeup and foundation.” Robbie held up a gloved hand. “I used to wear fingerless gloves, but not anymore! I tell ya, my Sire was a dick!”

Dipper nodded, feeling a bit dizzy. “Uhm...are we almost there?”

“Almost. You gotta be careful choosing your target, you could get someone who does drugs, or has AIDS.” Robbie shuddered.

They stopped in front of a building and Robbie went to the window and looked in. “Okay...looks like they're asleep. Normally we'd go to the park, but there's cops everywhere.” He looked at Dipper. “Think you can be seductive?”

“I'm twelve.” Dipper frowned.

“Hm, true. Wait here.” Robbie slipped into an open window, leaving Dipper outside to wait. A bit later, he came out with a bashful girl.

“We just need you to give a tiny bit, just like at the blood bank.” Robbie cooed as they approached Dipper.

“Well, I don't want a little boy to starve.” The girl pulled up a sports band from her wrist. “Go ahead, little one.”

Dipper swallowed nervously and moved closer, taking her wrist in his hands. He took in her scent and then parted his lips, clamping onto her wrist and digging his teeth in. She moaned softly and leaned against Robbie, closing her eyes.

After he drank his fill, he licked her wrist and she pulled her band over it to conceal it, the wound clean of blood.

“Thanks, doll.” Robbie kissed her cheek. “See you later.”

She giggled and went back in, Robbie rejoining Dipper. “Let's get you back to the hospital.”

“Who was that?” Dipper asked as they headed back.

“Someone I met shortly after I became a vampire. She's crazy into the occult.” Robbie said as they dodged cars again. “Anyways, I gotta get back to Gravity Falls soon. Good luck, kid.”

Dipper nodded, turning to watch him go. Then he went in, returning to his room.

 


	2. Gravity Falls

**Summary for the Chapter:**

> Mabel and Dipper head to Gravity Falls! Can Dipper find his Sire and a cure?

**Notes for the Chapter:**

> Gravity Falls (c) Alex Hirsch and Disney XD

“Do you think it's still a good idea?” Mabel asked as she packed her bags. “I mean, I've never even _heard_ of Gravity Falls, and we're not even being _driven_ there?”  
  
“Not to mention, our parents are leaving us alone with an uncle we haven't seen in years.” Dipper said, pulling out various hooded shirts and jeans to go into his bag. “Should I bring sunglasses?”  
  
“Well, it _is_ summer. And I'm bringing some.” Mabel held up her own sunglasses. “Seriously, that guy picked the _worst_ timing. What about the pool? Can you still go to the pool?”  
  
“Maybe an indoor pool.” Dipper shrugged.  
  
“And I had to find a bathing suit that covers my neck!” Mabel pouted.  
  
“It does look nice.” Dipper offered. “Even if it's not the two-piece you wanted.”  
  
“Oh well.” Mabel sighed dramatically. “They'll just have to settle without seeing my beautiful neck. Speaking of, how you feeling?”  
  
“It hasn't even been an hour, are you secretly enjoying this?” Dipper raised an eyebrow at her. “Wait, like, five to six hours. Fang-addict.” He lightly punched her arm.  
  
“Ouch, careful!” Mabel rubbed her arm.  
  
“Whoops. Still getting used to the strength.” Dipper cringed. “Will it bruise?”  
  
“Nah, I think we're good.” Mabel shook her head, but checked anyway. “Yeah, we're good.”  
  
Dipper breathed a sigh of relief. “Thank goodness.”  
  
Mabel nodded, lowering her sleeve. “Yeah, the last thing we want is to show up with a bruise on my arm.”  
  
“Kids? If we don't go now, you'll miss the bus!” Their mother called.  
  
Dipper cringed. “Should've packed sooner.” He zipped up his bags and carried them downstairs, Mabel following right behind after doing the same. He stopped to pull up his hood and then followed his mother and sister out to the car, cringing away from the sunlight.  
  
At his request, the family had gotten shades for the windows – not that they knew why, he was afraid to tell his parents, honestly. They buckled in and were on their way, heading for the bus depot. After a tearful goodbye with hugs and kisses, they were on the Speedy Beaver headed for Gravity Falls.  
  
Mabel talked excitedly about all the boyfriends and friends she was going to get, that THIS was the summer of romance! Dipper resisted the urge to roll his eyes at her twelve-year-old enthusiasm about boys and looked out the window. As usual, there was no reflection – and he kind of liked it. Without a reflection obscuring the outside, he could enjoy the view better. He had to find the silver-lining in the black cloud that was his life, didn't he?  
  
Gravity Falls...Robbie had said he lived there. That he was trying to find a cure. Maybe, just maybe, he could go home completely human again.  
  
Dipper hadn't told Mabel about Robbie, of course. If she knew he'd snuck out of the hospital, she'd freak! Especially if she knew he'd met up with his attacker again! No, Mabel would not get to know that little secret. Though he was glad he met Robbie again, since he was nice enough to give him tips on how to, say, NOT kill his sister when he takes her blood.  
  
Which she seemed to be enjoying a little TOO much, _awkward_. He'd have to ask if the toxin in the fangs were an aphrodisiac.  
  
 **–**  
  
Though the bus had been full when they first got on, by the time they saw the sign informing them on Gravity Falls on the next left turn, they were the only two passengers on the bus. Which was a good thing, because Dipper had needed blood right about that point and Mabel had pulled a blanket over them and was covering her mouth with a hand as Dipper took what he needed from her. It was a good thing she was so full of energy, otherwise she just might pass out! He finally finished and licked the wound before pulling away.  
  
Mabel pulled her sweater back on and moved the blanket, looking around. “Oh, wow! Look at all the trees!”  
  
Dipper looked out at them as well. “Yeah...wow.” He nodded.  
  
“Approaching Gravity Falls station, Gravity Falls station. Please make sure you have all your belongings before we stop.” The driver said over an intercom.  
  
They gathered their bags and made sure everything they took out was put back in. Then Mabel cleaned around Dipper's lips with a wet wipe before pocketing it. “Well...ready?”  
  
“A bit late to decide that.” Dipper said, looking at the bus depot as they came to a stop. “Let's go.”  
  
“Hood up.” Mabel nodded.  
  
Dipper pulled his hood up and then followed her out into the sunlight. To their surprise, no one was there to greet them.  
  
“Maybe they got the wrong time?” Mabel asked the air. Suddenly, smoke appeared in front of them and an old man in a black suit wearing a burgundy fez appeared with a grin. “Oh, Grunkle Stan!” She smiled.  
  
“Welcome, kids!” The man said, beckoning them to come closer. “Gave you a bit of a scare just now, didn't I?” He chuckled.  
  
“We thought we'd be stuck waiting.” Dipper said, walking over with Mabel.  
  
“Nah, I was just wanting to make an impression.” Stan chuckled and motioned for them to follow him. “C'mon, kiddos, let's get you home!” He motioned to the car ahead of them and then they got in. As they buckled into the back, he adjusted the mirror and glanced at Dipper. 'Uh oh, that's not good.' He thought. 'Just how many kids are changing lately? This is the second one without a reflection I've seen in a month...'  
  
Mabel looked at Dipper. “You alright?” She asked quietly as the engine started up.  
  
Dipper nodded. “I'm alright. Hood keeps the sun away.”  
  
Mabel nodded and took his hand, squeezing it gently, and then they looked out the window as they drove to their summer home  
  
 **\--**  
  
The Mystery Shack was a nice enough place. It was a pleasant little building, with a kitchen, one bedroom, an attic that had been made into a bedroom for the two of them, a bathroom, and an area that was full of knick-knacks, which was where Stan ran his business and cut off the rest of the house with an “Employees Only” sign. Stan showed them to their attic room and then left them to unpack. Dipper took one look at the goat that was hanging out on the bed Mabel hadn't claimed “in the name of Mabel” and it bolted.  
  
He supposed his not-human state could have something to do with it...  
  
“This is great!” Mabel hopped off her bed and started to unpack. “And look at the view!”  
  
“Mm, I'll take a look when it's not shining direct sunlight at me.” Dipper said, deliberately avoiding standing in front of it. He unpacked and handed Mabel his clothes, which she put in the dresser for him.  
  
“Let's go downstairs.” She suggested with a smile.  
  
He looked thoughtful. “Sure.” He nodded, heading for the door first. Mabel finished putting up the curtain over the window and followed him down.  
  
“Hey, you're here! Good, I wanted to introduce you kids to someone.” Stan nodded towards the shop.  
  
“Alright.” Dipper nodded, walking into the shop. He pulled his hood up again as they entered, seeing as the door was frequently opening and closing.  
  
Stan walked out with them. “Kids, I want you to meet Wendy. Wendy, these are my great-niece and nephew.”  
  
The girl behind the counter was an Amazonian beauty with long, red hair and green eyes. Dipper felt himself hungering, but it wasn't for her blood – even if she did have a beautiful, long neck.  
  
“Hey, dudes!” She waved. “Rockin' the hoodie, huh? Reminds me of my friend Robbie.” She grinned.  
  
Dipper jolted out of his daze. Wendy knew Robbie? Did she know what Robbie was? Mabel and Wendy conversed about something, but he'd stopped paying attention when she mentioned Dipper's Sire.  
  
“Anyways, I better get back to work. What're you planning for the day?” Wendy asked.  
  
“We were thinking about exploring.” Mabel looked at Dipper.  
  
“Well, don't get lost.” Wendy looked at a customer walking in. “It was neat talking to you, dudes.”  
  
Mabel nodded and pulled Dipper out with her. “Okay, why were you spacing out?” She asked.  
  
“Spacing? Uhh, who's spacing? Let's go into the woods.” Dipper walked into the shade of the trees.  
  
Mabel rolled her eyes and followed him. “You were, space-case. Ever since we--” She cut herself off with an excited gasp. “Ohhhhhh, does someone have a _crush_?  Oh my goooooosh! You should've told me!”  
  
“Mabel...” Dipper frowned.  
  
“Don't worry, bro-bro! The Love Expert is on the ca—”  
  
“Mabel!” Dipper raised his voice. “Right now, I don't want to get romantically involved with someone, okay? I mean, one second we're kissing and the next thing we know, they're LUNCH!”  
  
“Okay, I can see how that would put a damper on the relationship.” Mabel frowned.  
  
“You think?!” Dipper sighed. “I appreciate the offer, Mabel, but I just can't risk it right now.” He sat down on a stump, staring at the ground. “I can't risk turning into a monster around her...”  
  
“Probably a good idea.” Mabel nodded, sitting on the stump as well – though to do this, she had to sit on his lap.  
  
“Hey, get your own stump!” Dipper laughed, nudging her back.  
  
“Nah, this is comfy.” She adjusted a bit to get comfortable and grinned at him over her shoulder.  
  
“Nooo, you have sister-weight!” He acted like she was much heavier than she was.  
  
“Oh, really? You know what else I have?” Mabel got off of Dipper and raised her manicured, painted nails.  
  
“Uh oh.” Dipper got up.  
  
“Get back here!” Mabel lunged at him. Dipper yelped and laughed as he side-stepped her. “Hey, don't you dare use your super-speed! You never talk about a lady's weight, now take your punishment obediently!”  
  
“Noooo!” Dipper laughed, stepped out of her reach again.  
  
“I'm gonna get you when you least expect it, may as well take it like a man right now!” Mabel wriggled her fingers at him.  
  
“Nope, not happening!” Dipper climbed up a tree, staring down at her from a branch half-hidden by the leaves.  
  
“Okay, jaguar, come on down.” Mabel put her hands on her hips. “That's enough of this silliness.”  
  
“You have to promise not to tickle me.” Dipper said from his hiding place.  
  
“Only if you promise not to make a comment about my weight again.” Mabel raised an eyebrow at her.  
  
“Alright, deal.” Dipper climbed back down.  
  
“Thank you.” Mabel patted him on the head and then ran off laughing.  
  
Dipper chuckled and started after her, but paused and turned to look behind him. Had he felt someone watching him? After making sure Mabel wouldn't hear, he looked behind him again and whispered “Robbie?”  
  
No answer. Sighing, he ran after Mabel.  
  
After he left, a figure looked out from behind a tree. They started to take a step closer, but the moment they tried to pass a stone with a symbol carved on it, smoke started to come from their foot and they pulled it back.  
  
Grinding their teeth, they stepped back into the shadows of the trees.

 

**Notes for the Chapter:**

> Hm, a strange person watching Dipper in the woods. That's not gonna lead to trouble!

**Author's Note:**

> Will Dipper find a cure, or be stuck as a vampire forever?


End file.
